| 摘要 |
PROBLEM TO BE SOLVED: To provide a navigation device capable of evading an unreadable state of map data. SOLUTION: A navigation controller 1 is configured comprising a hard disk device 2 storing map data necessary for map display, etc., a map read control part 18 for reading the map data stored in the hard disk device 2, and a data expanding part 19 for reading the compressed map data and expanding them. By storing compressed map data in the hard disk device 2 separately from the map data for usual use for reading and partially expanding the compressed map data of an area around own vehicle beforehand during halt of the vehicle, the expanded map data can be read out in case read error occurs at a time of reading the map data. |
